I am switching from prozac (was on 80mg for 4 weeks, didn't work lowered back to 40mg for 1 week then will start Zoloft (sertraline) 100mg instead) What to expect?

Hope for Success. I don't think you will experience any withdrawal symptoms. Prozac has a long half-life and takes a couple weeks to clear from the body. It is common to switch from one SSRI to another. I hope the change works for you. The medication Zoloft (sertraline) is usually well-tolerated with very few side effects. Sometimes it takes up to 8 weeks for med to work. Give it some time. Best wishes!